Many types and mixtures of metal salts and soaps of natural or synthetic organic acids, particularly carboxylic acids, have been suggested and commercially offered over several decades. These have been used to supply metals in forms which are soluble in organic liquids, especially in various hydrocarbon oils and solvents, to form solutions having various desired properties and uses. For example, such metal salts have found use as catalysts, or as fuel and lubricant additives.
Bismuth carboxylates have achieved notoriety as a catalyst system for preparing polyurethane elastomers. U.S. Pat. Nos. 4,584,362 and 4,742,090 provide detailed examples of how to use bismuth salts of carboxylic acids having from 2 to about 20 or 30 carbon atoms, respectively, and these patents are incorporated herein by reference.
It is also known that the preparation of polyurethanes from diisocyanates containing uretdione rings may be catalyzed by the presence of a bismuth salt of an organic carboxylic acid preferably having from 2 to 20 carbon atoms, such as disclosed in U.S. Pat. No. 4,786,655 incorporated herein by reference.
Other catalytic applications for bismuth soaps include curing organosiloxanes (U.S. Pat. No. 2,843,555), copolyesterification of terephthalic acid (U.S. Pat. No. 3,245,959) and oxidation of unsaturated aldehydes (U.S. Pat. No. 4,093,649).
Another field of use for this class of compounds is in the area of treatment of cracking catalysts. U.S. Pat. No. 4,083,807 discloses an improved catalytic cracking catalyst obtained by incorporating into a crystalline aluminosilicate catalyst by ion exchange a substantial concentration of a metal selected from the group consisting of antimony, bismuth and manganese, wherein the ion exchange is conducted with organic salts of antimony, bismuth and manganese.
Metal salts from polyvalent metals, such as mercury, copper, and bismuth may be used as driers in a drying oil composition which, when applied in the form of paints or coatings, can repel marine organisms and prevent mold and decay as disclosed in U.S. Pat. No. 1,933,520.
As various organic carboxylic acids have become available in commercial quantities, either from new natural sources, or as synthetic acids or standardized synthetic acid mixtures, the possibility of using these to produce metallic salts or soaps has been motivated, for example, by a lower price, by a relative uniformity of the commercial acids, by a better color or noncolor, by higher solubility of the salt products in various solvents in other components of ultimate products for which the metal salt is to be used, or stability in storage of the metal compositions or of their solutions. Bismuth carboxylates are an attractive non-toxic alternative to toxic metal catalysts and paint driers (such as cadmium and lead containing catalysts and driers). Neutral salt or soap compositions contain one mole of a carboxylate group per equivalent of metal present.
An early disclosure of a method for producing metal salts of organic acids using saturated aliphatic monocarboxylic acid having 1 to 8 carbon atoms, a metal having a normal potential between -0.80 and +0.5 volt, and an oxygen-containing gas as an oxidizing agent may be found in U.S. Pat. No. 3,133,942.